Segment Reporting (Schedule Of Operating Information, Segment) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Net revenues	[1]	$ 742,732	$ 725,647	$ 1,493,090	$ 1,401,178
Income/(loss) before income taxes		118,347	83,198	237,901	162,217
Global Wealth Management [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	497,327	451,990	982,902	894,722
Income/(loss) before income taxes		187,895	153,237	364,666	295,289
Institutional Group [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	252,825	276,153	522,903	513,620
Income/(loss) before income taxes		36,024	52,892	80,594	92,764
Other [Member]
Segment Reporting Information [Line Items]
Net revenues	[1]	(7,420)	(2,496)	(12,715)	(7,164)
Income/(loss) before income taxes		$ (105,572)	$ (122,931)	$ (207,359)	$ (225,836)

[1] No individual client accounted for more than 10 percent of total net revenues for the three and six months ended June 30, 2018 or 2017.